This paper reports on a survey of library membership and circulation figures from seven Tanzanian regional libraries over a 4-year period which was undertaken to evaluate the performance of the Tanzanian Library Service in its capacity as a national network providing free library service, promoting education as a lifelong process, and supporting literacy and adult education programs for the Tanzanian populace. Standards for the measurement of library performance are outlined with respect to the utility of library facilities, the availability of library materials, and the variables affecting the quality of user services. Results of the survey are presented, with an emphasis on the reasons given by the libraries surveyed for the decline in library issues over the period studied. A series of suggestions for the reversal of the declining trend in library use made by the survey respondents is then reviewed. A summary of the survey results in relation to the Tanzanian library environment closes the report. A reference list and set of data tables accompany the text. (JL)